alias not allowing zero argument tags

[gilch]

For example,

builtins..float#*=()

is 0.0, but

bn##float *=()

is float, just like bn#float. I'm not sure it's possible for the alias metaprogram to distinguish these cases, and I'm not sure how to fix this even by modifying the reader. I might have to rethink the tag system. This is perhaps an argument for including aliases in the reader directly as a special case (more like Clojure does) rather than implementing them as a meta-metaprogram.

The workaround would be

.#(bn#float)

which uses the abbreviated alias and also calls it at read time with zero arguments. I'll at least document this in the wiki.